Upholstery insulator pad



J1me 1966 w. F. RICHARDSON 3,256,535

UPHOLSTERY INSULATOR PAD Filed Oct. 29, 1963 NHR INVENTOR MY/I'JI/V E Flt/rarefied Affa/wey.

United States Patent 3,256,536 UPHOLSTERY INSULATOR PAD William F. Richardson, Carthage, Mo., assignor to Flex- 0'- Lators, Inc., Carthage, Mo., a corporation of Missouri Filed Oct. 29, 1963, Ser. No. 319,721 6 Claims. (Cl. -354) This invention relates to new and useful improvements in upholstery accessories, and has particular reference to a protective load distributing sheet adapted to be placed between the supporting spring deck and the padding layers of upholstered furniture, automotive seating and the like, said protective and load distributing sheets beingcommonly known as insulator pads. Such pads have the functions of distributing the load applied to the cushion over a Wider area of the spring deck, which is commonly composed of a relaively small number of widely spaced spring elements such as vertical coil springs or zigzag spring elements, and of preventing the padding material thereabove from working downwardly into the spaces within or between the spring elements forming the deck.

One type of insulator pad in extremley common usage consists of a sheet of burlap or other pliable sheet material having spring steel wires stitched therethrough in parallel, spaced apart relation. The wires are secured against longitudinal slippage in the sheet by the fact that the corresponding ends of all the wires are twisted or knotted about the pliable side strands extending transversely to the wires. However, this structure just described has been subject to the disadvantage that in order to insure the bulk necessary to insure that the wires could not pull the side strands themselves through the fabric sheet, said side strands were necessarily rather thick and bulky. A twisted paper cord of about A in. diameter has commonly been employed for this purpose. As a result, the side cords often created a linear bulge which was plainly visible through the overlying padding material, such bulges of course being unsightly and hence highly objectionable. The problem is the provision of a means securing the wire ends to prevent positively any longitudinal slipping or creeping of the wires, which will not substantially decrease the pliability of the fabric sheet about axes parallel to the wires, and which has sufficiently small bulk not to create visible bulges in the upholstery. It is extremely difiicult to secure the end of a Wire in such a sheet, since the sheet or fabric is locally far too fragile to retain a wire of a hook formation of the wire simply pierces the sheet. The hook will simply tear free. Also if the wire is formed to present a flat loop or other enlargement adjacent the last stitch thereof through the sheet, the enlargement will tear through the last stitch hole of the sheet, or spread the threads of the sheet if it comprises a fabric, and pull free.

One proposed solution for the problem has been to gather or bunch a small area of the sheet into a multiple fold which in effect constitutes a side cord about which the associated ends of the wires can be tightly looped, the gathering providing a sufiicient strength to allow firm retention of the Wires. However, this structure is at best only a partial solution, since the gathering or bunching of the sheet still forms a bulk which may be visible through the padding material, and the structure is difficult and expensive to manufacture.

See

Accordingly, the principal object of the present invention is the provision of an insulator pad which solves all of the above discussed problems, in the that a novel means is provided which securely fastens the wires against longitudinal slippage, but which is nevertheless of sufficiently small bulk that it does not create a bulge which can be seen even though very thin padding material layers may be laid thereover, and which does not inhibit the pliable bending or folding of the sheet along lines parallel to the wires.

Other objects are simplicity and economy of construction, efficiency and dependability of operation, and adaptability for production in continuous lengths by automatic machinery.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the accompanying drawing, wherein:

FIG. 1 is a plan view of a furniture insulator pad embodying the present invention, partially broken away, and

FIG. 2 is an enlarged, fragmentary sectional view taken on line IIII of FIG. 1, with the relative positions of the parts slightly altered for clarity.

Like reference numerals apply to similar parts in both of the views of the drawing, and the numeral 2 applies generally to the insulator pad forming the subject matter of the present invention, said pad consisting of a sheet 4 of burlap or other pliable sheet material, a continuous series of parallel, spaced apart spring steel wires 6 stitched through said sheet, and a pair of cords 8 each of which extends generally transversely to wires 6 at one end of said wires, said cords securing the wires against longitudinal slippage in sheet 4 as will presently be described.

Each of wires 6 has a loop 10 formed therein at each end thereof. Said loop is disposed at one face of sheet 4, which for convenience will be designated the upper face. Said loop normally lies substantially flat against the sheet, and is disposed directly adjacent the last point 12 at which the wire 6 pierces the sheet by virtue of the fact that it is stitched through said sheet. The next point 14 at which the wire pierces the sheet, so that a portion 15 thereof is again disposed above the sheet, is spaced apart from point 12 by a distance sufiiciently great that at least several longitudinal threads of the sheet. if said sheet is burlap, are included therebetween as indicated in FIG. 2. All other stitches of the wire through the sheet may be of any desired length, so long as they perform the function of maintaining a generally uniform spacing between the wires throughout their lengths. It

will be understood that the transverse width of sheet 4, in a direction parallel to the wires, may be as desired, the material usually being produced in a range of standard widths, and that the material is usually produced in continuous longitudinal lengths which may be cut off as desired, between an adjacent pair of wires 6, to fit the particular cushion being equipped with the insulator pad. Also, the pad usually has a width greater than the length of wires 6, whereby to form a flap 16 at each side thereof which is not wire-reinforced. Said flaps are utilized to fasten the pad to a spring deck, or directly to the furniture frame in which the spring deck is mounted, although this is not pertinent to the present invention.

Cords 8 are quite thin, preferably having a diameter no greater than about ;{32 /1 inch, and are formed of a pliable but tough material such as fibered nylon, although other materials could be used. Each cord extends transversely to wires 6, so that each of them traverses one of the ends of each of the wires. Said cord is threaded freely through the end loop 10 of each wire. Adjacent each of said wire loops, the cord has a loop or bight 18 formed therein, said bight being looped about portion of the associated wire. Also, the portions of the cord forming the opposite reaches of bight 18 are twisted together as indicated at 20.

Thus it will be seen that wires 6 are firmly secured against longitudinal slippage in the sheet as the pad is flexed repeatedly in a seat cushion or the like. Even if the end loop 10 of a wire should pull through sheet 4 at point 12, as could happen easily by tearing of the sheet at that point, or by parting the fabric strands if the sheet is formed of burlap or other textile material, and should therefore tend to pull the associated portion of cord 8 through the sheet with it, the portion of the sheet material between points 12 and 14 is still tightly gripped in a closed loop, one side of said loop being formed by wire 8 and the remainder of the loop being formed by the cord, particularly the twisted bight portion 20 thereof. This loop is clearly shown in FIG. 2. The amount of sheet material enclosed within said loop should be of suflicient strength, or sufficient extent, to distribute the strain of the wire pull thereon to enough of the sheet area to insure that it will not rip or tear out of the sheet. The length of the stitch of wire between points 12 and 14 will thus depend on the strength of the particular material of which sheet 4 is formed. It may be stated generally that for a burlap sheet, a distance of about onehalf inch between points 12 and 14 has been found adequate to provide the strength to resist any strains likely to be encountered in normal usage, while for a sheet formed of pliable plastic film or the like the distance should be somewhat greater.

The twisted portions 20 of the cords form effective knots, and may be so termed, which prevent the cord itself from pulling longitudinally through the wire loops 10 if subject to stress in that direction. These knots are extremely important to the eflicient operation of the device, since if the cords could pull out, it would free wires 6 so that they could become longitudinally displaced. A. more convenient knot, such as a common overhand knot, could be formed in the cord bights in place of the twisting at 20, and would be perhaps more eflicient than the twisting. However, conventional knots such as overhand knots are extremely difficult to form by automatic machinery, and the twisting has been found to be fully adequate to resist longitudinal displacement of the cords, particularly in view of the fact that the cords in actual usage are firmly pressed between sheet 4 and the overlying padding layers. This pressure resists any tendency of the cords to become untwisted, even at the longitudinal ends of the pads where, as at 22 at the top of FIG. 1, the cords may have been cut directly adjacent a twist 20 in fitting the pad to a seating structure. The number of turns needed in the twist also varies somewhat according to the nature of the cord, but the 2 /2 turn twist shown in the drawing has been found adequate even when the cord is quite smooth and slick.

Also, the pad as shown is sufficiently flat and thin, since wire loops 10 rest flat on sheet 4 and since cords 8 are of such small diameter, that even the end fastenings of the wires will not create a bulge which could be apparent through the overlying padding, even though said padding might be very thin. This is of course the most important object of the present invention. Also, since cords 8 are quite pliable, they do not in any way resisting folding or flexing of the pad around lines parallel to the wires, nor do they prevent the ends of the wires from being moved more closely together than shown. These features are important in permitting the pad to be fitted snugly and neatly over a convex or crowned spring deck without bunching or wrinkling.

The insulator pad is designed for rapid and economical production by automatic machinery wherein sheet 4 is advanced longitudinally in steps corresponding to the spacing between wires 6, past a work station, with cords 8 laid out along the edges thereof. The machinery then forms the two bights 18 for one wire and twists them together as shown at 20. At the work station a wire 6 is shot into position from a wire coil, sheet 4 being offset normally to its plane at intervals so that the wire, though straight, will be stitched into the sheet. As the wire is thus inserted, it passes through the bights 18, which are properly positioned to receive it. The wire is then cut to the proper length, and the ends thereof looped about the cords immediately adjacent the bights. The sheet is then advanced one step, another set of bights twisted into the cords to receive another wire, and so no. However, while this production method and apparatus is highly efiicient and economical, the invention resides in the product itself and the production method described is of course optional.

While I have shown and described a specific embodiment of my invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

1. An upholstery insulator pad comprising:

(a) a sheet of pliable material,

(b) a series of generally parallel, spaced apart spring wires each having a loop formed at each end thereof, said wires being stitched through said sheet whereby a portion of said sheet immediately adjacent each loop of said wires is disposed above said wire while said loop and the portion of said wire at the opposite end of the stitch are disposed above said sheet, and

(c) a pair of flexible cords extending generally transversely to said wires respectively at opposite ends of said wires, each of said cords being trained through the corresponding end loops of all of said wires, and having a bight formed therein adjacent each of said wire loops, said bight being looped about the associated wire at the end of the adjacent stitch distal from the loop of the wire.

2. An insulator pad as recited in claim 1 with the-addi tion of means securing each of said bights relative to the cord in which it is formed.

3. An insulator pad as recited in claim 1 wherein each of said cords passes through each of the associated wire loops in freely running relationship thereto.

4. An insulator pad as recited in claim 1 wherein each of said cords passes through each of the associated wire loops in freely running relationship thereto, and with the addition of means securing each of said bights relative to the cord in which it is formed.

5. An insulator pad as recited in claim 1 wherein each bight of said cords constitutes a bend in the cord, with the portions of the cord adjacent the bend being twisted together to secure the bight.

6. An upholstery insulating pad comprising:

(a) a sheet of pliable material,

(b) a series of generally parallel, spaced apart spring wires each having a loop formed at each end thereof, said wires being stitched through said sheet whereby a portion of said sheet immediately adjacent each loop of said wires is disposed above said wire, while said loop and the portion of said wire at the opposite end of said stitch are disposed above said sheet, and

5 6 (c) a pair of flexible cords extending generally trans- References Cited by the Examiner versely to said wires respectively at the opposite ends i of said Wires, each of said cords being trained through UNITED STA; ES PATENTS the corresponding end loops of all of said wires in ,1,144,123 6/1915 Haas freely running relationship thereto, and having a 5 2,233,116 5/ 1942 Yo ng 5 4 bight formed therein adjacent each of said Wire loops, 2, 49,399 3/ 1953 Williams 5-354 said bight being looped about the associated wire at ,7 ,2 8/1955 Hood 5354 the end of the adjacent stitch distal from the loop of the wire, said bight constituting a bend in the cord, FRANK SHERRY, 'y Examiner- With the portions of the cord immediately adjacent 10 NUNBERG Assistant Examiner the bend being twisted together to secure the bight. 

1. AN UPHOLSTERY INSULATOR PAD COMPRISING: (A) A SHEET OF PLIABLE MATERIAL, (B) A SERIES OF GENERALLY PARALLEL, SPACED APART SPRING WIRES EACH HAVING A LOOP FORMED AT EACH END THEREOF, SAID WIRES BEING STITCHED THROUGH SAID SHEET WHEREBY A PORTION OF SAID SHEET IMMEDIATELY ADJACENT WHILE SAID LOOP AND THE PORTION OF SAID WIRE AT THE WHILE SAID LOOP AND THE PORTION OF SAID WIRE AT THE OPPOSITE END OF THE STITCH ARE DISPOSED ABOVE SAID SHEET, AND (C) A PAIR OF FLEXIBLE CORDS EXTENDING GENERALLY TRANSVERSELY TO SAID WIRES RESPECTIVELY AT OPPOSITE ENDS OF SAID WIRES, EACH OF SAID CORDS BEING TRAINED THROUGH THE CORRESPONDING END LOOPS OF ALL SAID WIRES, AND HAVING A BIGHT FORMED THEREIN ADJACENT EACH OF SAID WIRE LOOPS, SAID BIGHT BEING LOOPED ABOUT THE ASSOCIATED WIRE AT THE END OF THE ADJACENT STITCH DISTAL FROM THE LOOP OF THE WIRE. 